This invention relates to trailer chassis and more particularly to security bolts especially adapted for holding dual wheels on a wheel hub mounted on the end of an axle thereof.
It is the practice to park a large number of trailers at terminals near a port for commercial navigation. The trailers are used to haul cargo to the port for placement on a ship and are then left at the terminals until needed again. Since the terminals are not being constantly guarded, the wheels, of which there are four pair on each trailer, often are stolen. This is especially a problem because of the ease with which the outer wheels can be slipped off the wheel hubs to which they are attached, without the need for jacking up the rear end of the trailer.
Conventionally the rims of a pair of inner and outer wheels with a spacer in between are slipped over the periphery of a wheel hub mounted on the end of a rear axle of a trailer chassis. The inner wheel rim engages flanges on the peripheries of spokes of the wheel hub and the outer wheel rim is engaged by end clamps attached by studs and nuts to faces on the outer ends of the spokes of the wheel hub.
In accordance with the present invention, the studs and hexagonal nuts provided on the faces of two of the five spokes of a wheel hub for holding the inner and outer wheels by their rims are replaced by security bolts. Each security bolt has a cylindrical head of such a diameter that when its threaded end is engaged on the wheel hub, the side of its cylindrical head substantially contacts the inside wall of the rim of the outer wheel. The cylindrical head of the security bolt is provided with an opening for receiving a non-standard size projection provided on one end of an adaptor whose opposite end is adapted to mate with the end of a standard wrench. With such a structural arrangement, it is very difficult to loosen the security bolts as needed to remove the wheels of the trailers while the trailers are being parked at terminals near a port, for example, thus preventing theft of the wheels.
Accordingly, one of the objects of the present invention is to provide for holding, i.e., effectively locking, wheels on a trailer by the use of security bolts which are designed so that they can not be removed with a standard wrench.
Still another object of the present invention is to provide for holding wheels on a trailer by replacing two non-adjacent studs and hexagonal nuts on the wheel hub with security bolts that require a special adaptor to effect their removal by the wrench used for removing the hexagonal nuts.
With these and other objects in view, the invention consists of the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.